Warning

Summary of activity in Bárðarbunga

State of events on Monday evening

19.8.2014

Summary written 18th August at 20:45

Since the onset of the earthquake swarm at Bárðarbunga on Saturday morning 16th August 03:00am, around 2.600 earthquakes have been detected with the earthquake monitoring network of the Icelandic Meteorological Office (IMO), of these around 950 since midnight (17/18th August). Several of these events were larger than magnitude 3. The swarm initially started in the Bárðarbunga caldera and has been migrating in two clusters towards the north and the east of the volcano.

On Sunday 17th of August, these two clusters were active east and north of Bárðarbunga. The activity in both clusters was migrating northeastwards. While the strongest events were located in the northern cluster, the highest number of events was detected in the eastern cluster. The strongest event since the onset of the swarm was detected on Monday morning 02:37 in the northern cluster. Detailed analysis revealed that its magnitude was 4.5 and it was felt in Akureyri and Lón. By Monday evening, activity has significantly decreased in the northern cluster.

The eastern cluster remains active. Two stronger pulses of activity have occurred between 10:45 and 12:00 as well as 16:50 and 17:30 this morning. Within the first pulse around noon, the cluster was again migrating northeastwards, most events are now located between Bárðarbunga and Kverkfjöll. As reported earlier, GPS ground deformation data has evidenced that the earthquake swarm is caused by magma intrusion.

Throughout the whole sequence until now (18th August at 20:45) the majority of events has been at 5-10km depth. No signs of migration towards the surface or any other signs of imminent or ongoing volcanic activity have been detected so far. IMO is monitoring the area around the clock very closely and will update in case of any changes.

Manually checked earthquakes

Fig. 1. All manually checked earthquakes since the beginning of the sequence. Event times are colour coded, events larger than magnitude 3 are given as green stars. The migration of the activity from the caldera of Bárðarbunga (dark blue, Saturday) to the northern and eastern clusters (light blue, Sunday; orange Monday) can be seen.

Automatically detected events

Fig. 2. All automatically detected events on Monday 18th August. It illustrates the migration of the eastern cluster to the northeast, colour coded by time, red dots show the latest events.

This news article was published 19.08.2014 at 09:43, citing a report from 18.08.2014 at 20:45.